• Abstract and Figures
• Public Full-text

International Journal on Recent and Innovation Trends in Computing and Communication ISSN: 2321-8169 Volume: 4 Issue: 6 340 - 345 _______________________________________________________________________________________________ Design and Analysis of Antiroll Bars for Automotive Application Mr. Khartode Ankush .N Prof. Gaikwad. Mahendra. U ME [Mechanical (Design Engineering)] DGOIFOE Swami- ME [Mechanical (Design Engineering)] DGOIFOE Swami- Chincholi Daund India Chincholi Daund India E-mail:[email protected] E-mail: [email protected] Abstract-Anti-roll bar, stabilizer or sway bar, is a rod or tube, usually made of steel, that connects the left and right wheels members together to resist roll or swaying of the vehicle which occurs during cornering or due to road irregularities. An anti-roll bar improves the handling of a vehicle by increasing stability during cornering or evasive manoeuvres. The bar's tensional stiffness (resistance to twist) determines its ability to reduce body roll, and is named as “shear stress or Rolling Stiffness”. More vehicles have front anti-roll bars. Anti-roll bars at both the front and the rear wheels can reduce roll further. The other function of anti-roll bars is to tune the handling balance of a car. Under steer or overseer behaviour can be tuned out by changing the proportion of the total rolling stiffness that comes from the front and rear axles. The stabilizer bars contribute thus considerably to the improvement of comfort of the motor vehicles. Keywords-Anti-sway bar, stabilizer bar, tensional angle, ,FEA, Automotive Design, Stress Analysis, Torsion Stiffness, Anti Roll Bar, Design Parameters, Bushing position, Rolling stiffness, Deflection. __________________________________________________*****_________________________________________________ I. INTRODUCTION A typical anti-roll bar is shown in Figure 1.1 Introduction to Anti-roll bar 1.1information. First, the anti-roll shear stress of the bar has Anti-roll bar, sway bar, is a rod or tube, usually made of direct effect on the handling characteristics of a vehicle. steel, that connects the right and left of the vehicle which The main goal of using anti-roll bar is to reduce the occurs during turning. The bar's torsion stiffness (resistance vehicle roll. Body roll occurs when a vehicle deviates from to twist) decides its ability to eliminate body roll, and is straight-line motion. The line joining the roll centres of named as “shear stress or Rolling (SSOR) Stiffness”. An wheels suspensions forms the roll axis of a body. Centre of anti-roll bar improves the handling of a vehicle by gravity of a vehicle is generally above this roll axis. Thus, increasing capacity during cornering or evasive manoeuvres. while turning the centrifugal force creates a roll moment More vehicles have front Anti-roll bars. Anti-roll bars at about the roll axis, which is equal to the develop centrifugal both wheels can reduce rolling further. Properly chosen (and force with the distance between the roll axis and the CG. installed), anti-roll bars will reduce vehicle roll, that in turns Anti-roll bars serve two or more key functions. First they leads to good handling and increased driver confidence. A reduce roll of body, as explained above, and second provide spring rate increase in the front or rear anti-roll bar will a way to again spreading cornering loads between the both produce under-steer effect while a spring rate increase in the wheels, which in turns, given the capability of modify rear bar will develop uncontrolled steer effect. Thus, sway handling characteristics of the vehicle. bars are also used to improve directional control and stability. One more benefit of that, it improves traction by 1.2 Principles: limiting the camber angle change caused by body roll. Anti- Anti-roll bar is also a torsion spring that resists body roll bars may have not regular shapes to get around chassis roll motions. It is usually constructed out of a steel bar, components, or may be much simpler depending on the car. formed into a "U" shape that join to the body at two points, There are two possible facts to be considered about the sway and at the both sides of the suspension. If the both wheels bars within the presented and second, the geometry of the move together, the bar rotates about its mounting points. bar is dependent on the shape of other chassis components, When the wheels move relative to each other, anti-roll bar is the anti-roll bar is a rod or tube that connects the right and subjected to torsion and forced to roll. Each end of the bar is left spring connected to last link through a movable joint. The sway bar Members. It is used in front suspension, rear suspension or end link join in turn to a spot near a wheel or axle, in both suspensions; don’t matter the suspensions is rigid transferring forces from a maximum loaded axle to opposite axle type or independent type. side. Due to that forces are transferred: 1. from the maximum-loaded axle 2. To the jointed last link via a bushing 3. To the anti-roll (torsion) bar via a Flexible joint 4. To the jointed end link on the opposite side of the body 5. To the opposite axle. Figure 1.1 Anti roll bars with control Arm The bar resists the torsion through its shear stress. The stiffness or shear stress of an sway bar is proportional to the 340 IJRITCC | June 2016, Available @ http://www.ijritcc.org _______________________________________________________________________________________________ International Journal on Recent and Innovation Trends in Computing and Communication ISSN: 2321-8169 Volume: 4 Issue: 6 340 - 345 _______________________________________________________________________________________________ stiffness of the material, the 4thpower of its radius, and the roll axis, which is equal to the product of centrifugal force inverse of the length of the arms(lever) (i.e., the shorter the with the distance between the roll axis and the (CG) centre arm(lever), the stiffness of bar is high). Stiffness is related to of gravity. This moment causes the inner suspension to the geometry of the mounting points and rigidity of the bar’s extend and to compress the outer suspension, thus the body sway. The increases stiffness of the bar, the more force roll occurs. required to move the wheels relative to both. This increases the amount of shear stress required to make the body roll. 1.6 Purpose and Operation In a turn the spring mass of the vehicle's body produces An anti-sway or anti-roll bar is subjected to force each linear force at the centre of gravity (CG), proportional to side of the vehicle to lower, or rise, to similar heights, to linear acceleration. Because the centre of gravity is usually reduce the sideways tilting (roll) of the vehicle on sharp not on the roll axis, the linearly force creates a moment corners, or large bumps. With the bar removed, a vehicle's about the rolling axis that tends to roll the body. (The rolling wheels can tilt much larger distances (as shown by the SUV axis is a line that connects the rear and front roll centres image). Although there are many variations in design, a (SAEJ670e)). The moment is called the rolling couple. Roll common function is to force the cross wheel's shock- couple is resist by the suspension rolling stiffness, which is a absorber, spring or suspension rod to lower, or rise, to equal function of the spring rate of the vehicle's springs and of the level as the other wheel. In a rapid turn, a vehicle tends to anti-roll bars. The uses of anti-roll bars allows designers to drop closer onto the outer wheels, and the sway bar soon eliminate roll without making the suspension's springs forces the opposite wheels to usually get closer to the develop stiffness in the vertical plane, which allows develop vehicle. As a result, the vehicle tends to "hug" the road body control with less compromise of quality. One effect of closer in a fast turn, where all wheels are closer to the body lean, a typical suspension geometry, is positive camber chassis (body). After the fast turn, then the downward on the outside of the turn and negative on the inside, which pressure is reduced, and the paired wheels can return to their reduces their cornering grip (specific with cross ply tires). normally height against the vehicle, kept at similar levels by the connecting sway bar. Figure 1.2.1Basic Properties of Anti-Roll Bars Figure 1.6.1SUV 1.5 Connections Sway bars are connected to the other chassis (body) One way of estimating antiroll bar stiffness: components via 4 attachments. Two of these are the rubbers T=Vehicle track width (inches) bushings through which the sway bar is attached to the K=Fractional lever arm ratio (movement at rolls bar / frame. And the other two attachments are the fixtures movement at wheels) between the suspension members and the sway bar ends, d=Bar diameter (inches) either through the use of directly. R=Effective arm length (inches) L=Half-length of bar (Inch) S=Length of arm(lever) (inches) Q=Stiffness (lb*in per degree) Because each pair of wheels is cross-connected by anti-roll bar, the combined operation causes all wheels to generally offset the separate tilting of the others and the Figure 1.5.1Rubber bushings There are two major types of anti-roll bar bushings body tends to remain level against the general slope of the given according to the axial movement of the sway bar in terrain. A negative side-effect of joining pairs of wheels is the bushing. In both types, the bar is free to rotate in the that a bump to one wheel tends to also jar the opposite bushing.

Load more

  6

Copy Link